X-ray

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  • X-Ray
definition
  • X-Ray (Or x-radiation, Rntgen ray) is electromagnetic radiation with wavelengths shorter than that of ultraviolet radiation and greater than that of gamma radiation.

    Discovered accidentally by Rntgen in 1895. The primary mechanism for the production of x- rays is deceleration of a rapidly moving charge upon interaction with matter (bremsstrahlung). The x-ray spectrum from an x-ray tube consists of this continuous spectrum on which are superimposed narrow bands (characteristic radiation) that are a consequence of transitions between electronic energy levels of atoms. No sharp boundary exists between x- and ultraviolet radiation nor between x- and gamma radiation, although the latter term is usually restricted to radiation resulting from transitions between nuclear energy levels.

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Abstract from DBPedia
    An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 145 eV to 124 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it on November 8, 1895. He named it X-radiation to signify an unknown type of radiation. Spellings of X-ray(s) in English include the variants x-ray(s), xray(s), and X ray(s). The most familiar use of X-rays is checking for fractures (broken bones), but X-rays are also used in other ways. For example, chest X-rays can spot pneumonia. Mammograms use X-rays to look for breast cancer.

    X線(エックスせん、英: X-ray)は、波長が1 pm - 10 nm程度の電磁波である。発見者であるヴィルヘルム・レントゲンの名をとってレントゲン線と呼ばれることもある。電磁波であるが放射線の一種でもあり、X線撮影、回折現象を利用した結晶構造の解析などに用いられる。呼称の由来は数学の“未知数”を表す「X」で、これもレントゲンの命名による。 1895年11月8日、ドイツのヴィルヘルム・レントゲンにより特定の波長域を持つ電磁波が発見され、X線として命名された。この発見は当時直ちに大反響を呼び、X線の発生について理論的方向付けを与えようとしたポアンカレは1896年1月に、蛍光物質とX線の関連について予測を述べた。その予測に従い、翌月の2月にアンリ・ベクレルはウランを含む燐光体が現代からいえば放射性物質であることを発見するなどX線の発見は原子核物理の端緒となった。 日本の法令の条文上では片仮名を用いて「エックス線」若しくは「エツクス線」(ツを小文字を使わずに表記する)と表記するのが原則となっている。

    (Source: http://dbpedia.org/resource/X-ray)